If you're a mom and pop and always wanted a fancy consultant on your payroll for tasks ranging from accounting to building a mobile-social media strategy—there's a new start-up just for you.

Hourly Nerd.com is an online marketplace that offers MBA students for hire from the nation's top business schools. Fees range from $10 to $50 an hour ballpark. Those with deeper resumes charge up to $75 to $100 an hour.

The start-up is the brainchild of three Harvard Business School students—all under 30: Rob Biederman, 26; Peter Maglathlin, 27; and Patrick Petitti, 29. And like many entrepreneurial light-bulb moments, the idea was born from necessity.

An MBA degree can be pricey and students have the time to devote eight to 10 hours a week to short-term projects. Meanwhile, small-business owners broadly are at an interesting inflection point in a U.S. economy that's trying to gain traction.

Main Street needs to expand business organically again—but can't afford hires. And they certainly can't shell out for help from a fancy consulting, accounting or investment-banking firm.

That's where Hourly Nerd.com comes in.

"Small businesses need to start growing revenue again because there's no more cost cutting," co-founder Biederman said. "They need to explore ways of growing revenue without committing to a full-time hire," he said.

How Hourly Nerd.com Works

The start-up features a database of about 450 MBA students from the top business schools in the country, as well as international MBA students. No riffraffs here. The co-founders said quality of students is important to their business model's success.

Top students are matched with small-business projects—ranging from bookkeeping to, say, building a social media strategy to better reach customers.

The start-up idea, part of a Harvard class project, launched in February and quickly gained steam through word of mouth. Initial business clients included a Boston area florist, deli, gym, restaurant-bar and start-ups. Hourly Nerd.com has about 30 projects under its belt—and counting.

Even in such a short time after launch, the start-up is noticing smaller mom and pops generally need help formulating concepts and strategies. In contrast, larger small- to medium-sized businesses with millions in annual revenue seek help on specific projects and tasks, said Petitti, a co-founder.

Lest you forget, the three wunderkinds still need to finish their MBAs. Additionally in May, Hourly Nerd.com is scheduled to transition from a Harvard curriculum requirement to a for-profit business. The trio is planning for a first round of financing.

American Entrepreneurship, Thriving?

The Hourly Nerd trio is innovating, when Main Street broadly remains stuck in the doldrums. Constantly changing business technology and software tools don't help.

Co-founder Biederman, whose father is a small-business owner, has noticed some entrepreneurs need help mastering the latest financial tools and spreadsheets. "It's something that would take a couple hours for them and I was able to problem solve really quickly," Biederman said.

Beyond technology hurdles, smaller employers have been facing headwinds from Washington. There has been a heavy cloud of uncertainty about anticipated spending cuts and costs associated with Obamacare that go into effect in 2014.

But unlike larger private sector businesses, smaller employers usually don't have buffers such as large cash reserves to ride out federal budget cuts. Most smaller firms also can't pivot business strategies to ride out downturns. So their strategy has largely been staying in a holding pattern—including hiring decisions.

Fred Deluca, the founder of privately held Subway Restaurants, said the government is simply out of touch with small-business owners. Policies including Obamacare discourage entrepreneurship, and he would not have been able to start his franchise in today's environment, Deluca told CNBC's "Squawk on the Street" in February.